Abstract: Deinking of impact and nonimpact printed paper is accomplished by repulping the printed paper in an alkali aqueous medium containing a deinking composition comprising one or more nonionic surfactants and/or alkanols. The presence of the deinking composition causes ink particles to agglomerate, which are removed from the aqueous medium by size and density separation. The invention provides an agglomeration method with high ink removal from all types of impact and nonimpact printed paper.

Abstract: Recycling of mixed wastepaper, including plastic coated paper and printed paper, is accomplished by repulping the wastepaper mixture to disperse paper fibers, ink and plastic components into a pulp medium. Contact with a deinking chemical causes attraction between the ink components to form larger ink particles. The ink is adsorped onto the plastic components to form ink/plastic clusters which are removed to produce a substantially ink and plastic free pulp medium. Recycled paper products with improved strength comprising paper fibers from pulp medium produced in accordance with the method of the invention are also provided.

Abstract: A high level of calcium carbonate filler is added to secondary fiber pulp by in situ attachment to the secondary fibers. The secondary fiber pulp is mixed with an alkaline salt such as calcium oxide or calcium hydroxide and contacted with a reaction gas such as carbon dioxide in a gas-liquid contactor apparatus through efficient mixing in order to precipitate filler material such as calcium carbonate crystal complexes on the secondary fibers. The resulting pulp products have comparable or, in some cases, better brightness, cleanliness, and other sheet properties as compared to filler addition by conventional methods.

Abstract: Deinking of impact and nonimpact printed paper is accomplished by repulping and defibering the printed paper in an alkali aqueous medium containing a deinking chemical to form an ink pulp medium. The presence of the deinking chemical causes separation of ink particles from the printed paper fibers. Removal of the ink particles from the ink pulp medium is accomplished by screening, flotation, forward cleaning, reverse cleaning, washing and mechanical dispersion procedures to produce a substantially ink free pulp medium. This substantially ink free pulp medium has a speck removal and brightness level sufficient to produce a high-grade recyclable grade paper product. The invention provides a deinking composition comprised of a mixture of one or more solvents, and nonionic and anionic surfactants, capable of high ink removal from all types of impact and nonimpact printed paper.